Guard reconcileFromServer() with a syncStartTime so that entries
modified locally during an active performSync() cycle are never
overwritten by stale server data. This prevents the race condition
where a user removes a meal plan entry while Phase 2 of sync is
still iterating server recipes.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Introduces weekly meal planning with a calendar-based tab view, per-recipe
date assignments synced via Nextcloud Cookbook custom metadata, and 30-day
automatic pruning of old entries on load, save, and sync merge.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
